SHELDON SHKOLNIK, 52, LEADING CONCERT PIANIST

Sheldon Shkolnik, one of the Midwest`s leading concert pianists and a beloved figure in the musical life of Chicago, died Saturday at his home in Rogers Park after a long illness. He was 52.

The Chicago native was familiar to many area concertgoers for his numerous appearances with the Chicago Symphony Orchestra and the Grant Park Symphony, as well as for his recitals and chamber music concerts.

Mr. Shkolnik concertized widely across the country and performed with many major American orchestras, including the St. Louis Symphony, Detroit Symphony and San Francisco Symphony.

His repertory ranged widely, but he was perhaps best known for his brilliant performances of the big Romantic works.

A champion of American piano music, he gave the local premieres of piano concertos by John Corigliano, Jan Bach and John LaMontaine. His performance of Gershwin`s ''Rhapsody in Blue'' as part of a 1979 Independence Day concert at Grant Park drew a crowd of 350,000.

Mr. Shkolnik studied piano with Rudolph Ganz at the Chicago Musical College and Rosina Lhevinne at the Juilliard School of Music, where he received a master`s degree. He was composition student of Darius Milhaud.

The pianist made his Chicago Symphony solo debut at age 19 in 1957.

For his New York debut in 1966 at Philharmonic (now Avery Fisher) Hall in Lincoln Center, he played the Shostakovich Piano Concerto No. 1, with Thomas Dunn conducting.

Mr. Shkolnik`s final public appearances were at the world-premiere performances March 15-17 in Orchestra Hall of Corigliano`s Symphony No. 1 by the Chicago Symphony under the direction of Daniel Barenboim.

Corigliano, the CSO`s composer-in-residence, had dedicated the new work to several close friends who had died or were dying because of AIDS.

Although Mr. Shkolnik was not named in the score, Corigliano acknowledged that he had written the first movement, ''Apologue: Of Rage and Remembrance,'' specifically as a tribute to Mr. Shkolnik.

In the middle of the movement, Corigliano employs a quotation of an Isaac Albeniz tango that Mr. Shkolnik often performed. The score indicates that the piano piece is to be heard from an offstage piano.

For the CSO performances, the keyboard part was taken by British pianist Stephen Hough as a gesture of respect for Mr. Shkolnik.

''I think Sheldon kept himself alive just to hear the (Corigliano)

Symphony,'' said Chicago pianist Ramon Salvatore, a friend who had visited Mr. Shkolnik several times during his illness. ''He attended every one of the rehearsals and concerts even though he was very weak and wasn`t able to talk. I`m sure the effort of doing so shortened his life, but he felt it was something he had to do.

''He was a world-class pianist and a great musician,'' Salvatore added.

''His death is a great loss to me personally and to the local music scene.''